How Baby Sleep Works
Having an understanding of the science behind your baby’s sleep can give you realistic expectations and help you understand why certain things are happening with your baby and their sleep. It can help you troubleshoot sleep challenges and know if something is a problem or when it’s just a normal developmental stage in their sleep journey. We also think understanding your baby’s sleep can help you give your baby, and yourself, more grace and patience.
Sleep is a cycle with different stages.
Newborns are born with only two sleep stages: Deep Sleep and Active Sleep.
You can recognize these stages very easily. During active sleep, newborns grunt, twitch, smile, and they may even cry out in their sleep. During deep sleep, it’s practically impossible to wake them, even if you wanted to.
As a newborn sleeps, they move through active sleep to deep sleep and then either wake all the way up or drift back into active sleep for another sleep cycle.
Click below to watch a video of a newborn in active sleep:
Did you know you can help your baby sleep better starting from day one? Our Newborn Class teaches you everything you need to know to lay the foundation for healthy sleep from the very beginning.
The Four Month Sleep Regression
Between 3-5 months of age, a baby’s sleep goes through a developmental change and they begin experiencing the same sleep cycles as adults (this is commonly known as the 4 Month Sleep Regression).
Their sleep cycles split into 4 distinct stages. We won’t bore you with the details, but the important takeaway is that when babies and adults finish a sleep cycle, we all experience a partial arousal, or a mini waking.
It looks like this:
When adults complete a sleep cycle and experience this brief awakening, we might open our eyes and look around to see that everything is how it should be, but then we almost always fall right back to sleep and begin a new sleep cycle. We may not even realize we woke up because it happens so quickly.
Babies do this, too. They experience these same brief awakenings multiple times a night (sleep cycles last 60 to 90 minutes and increase in length to 120 minutes as your child grows). They check on their surroundings to make sure they’re safe and everything is the same as it was when they fell asleep.
If a baby doesn’t know how to fall asleep on their own (if they depend on someone or something else to help them fall asleep - nursing, bottles, rocking etc) they will fully wake up between sleep cycles and won’t know how to put themselves back to sleep on their own.
If your little one (5 months - 2.5 years) is struggling with being able to fall asleep on their own and connect their sleep cycles, we can help! We can work one on one with you to create a custom, step by step plan with ongoing support to help your baby or child sleep. Schedule a free discovery call HERE.
Circadian Rhythm \ Internal Clocks
Sleep is regulated by our circadian rhythms (or internal clocks) which tell us when we are supposed to be awake and when we are supposed to sleep. Light plays a huge role on our internal clocks. Exposure to light stimulates parts of the brain that control hormones (like melatonin production), body temperature and other functions that play a role in making us feel sleepy or wide-awake.
Newborn’s circadian rhythms are very immature at birth. After about 12 weeks, their internal clocks (circadian rhythms) are more mature. Light and darkness now play a huge role in their sleep.
We have tons of free resources on our blog, our podcast, and our Instagram. We also have an online Newborn Class that will help you set your newborn up for the best possible sleep by laying a solid foundation right from the start.